Answer:
1356.33 g/mol
Explanation:
Number of hydrogen in 1 molecule of cyanocobalamin = 88
Molar mass of hydrogen = 1.008 g/mol
So, Mass of hydrogen in one mole of cyanocobalamin = 88*1.008 = 88.704 g
Also, Given that mass of hydrogen is  6.54 % Of the mass of cyanocobalamin.
Thus,
[tex]6.54\ \%=\frac{Mass_{hydrogen}}{Mass_{cyanocobalamin}}\times 100[/tex]
So, Applying values, we get:
[tex]0.0654=\frac{88.704}{Mass_{cyanocobalamin}}[/tex]
Mass of 1 mole of cyanocobalamin = 1356.33 g
So, molar mass = Â 1356.33 g/mol